A cut or crush injury to a peripheral nerve results in the degeneration of that portion of the axon isolated from the cell body. The rapid degeneration of this distal segment was for many years believed to be a process intrinsic to the nerve. It was believed that Schwann cells both phagocytosed degenerating axons and myelin sheaths and also provided growth factors to promote regeneration of the damaged axons. In recent years, it has become apparent that the degenerating distal segment (...) is invaded by monocytes from the blood. We will review the evidence that these recruited macrophages play a role in both degeneration and regeneration of peripheral nerve axons after injury and consider whether the slow degeneration and poor monocyte recruitment in the central nervous system may contribute to the poor regeneration there. (shrink)

Science fiction is often held up as a particularly philosophical genre. For, beyond actualising mind-experiment-like fantasies, science fiction films also commonly toy with speculative ideas, or else engineer encounters with the strange and unknown. Denis Villeneuve's Arrival is a contemporary science fiction film that does exactly this, by introducing Lovecraft-esque tentacular aliens whose arrival on Earth heralds in a novel, but ultimately paralysing, inhuman perspective on the nature of time and reality. This article shows how this cerebral film invites viewers (...) to confront a counterintuitive model of time that at once recalls and reposes what Gilles Deleuze called a “third synthesis” of time, and that which J. M. E. McTaggart named the a-temporal “C series” of “unreal” time. We finally suggest that Arrival's a-temporal conception of the future as having already happened can function as a key to understanding the fate of humanity as a whole as we pass from the anthropocene, in which humans have... (shrink)

Accumulating evidence indicates that simulated natural settings can engage mechanisms that promote health. Simulations offer alternatives to actual natural settings for populations unable to travel outdoors safely; however, few studies have contrasted the effects of simulations of natural settings to their actual outdoor counterparts. We compared the impacts of simulated and actual natural settings on positive and negative affect (mood) levels using a pooled sample of participants enrolled in extant experimental studies. Relevant articles were identified from a review of research (...) published/in press by March 2020 and updated during the peer review of the current study. Of 16 articles identified, 6 met the inclusion criteria and administered a single cross-cutting, standardized instrument [the Positive and Negative Affect Schedule (PANAS)] before and after exposure. Random effects meta-analysis of pooled effects showed that positive affect increased in the actual settings but not in their simulated counterparts (Hedge's g = 0.87; 95% CI, 0.54, 1.20). We observed little difference in effects on negative affect change scores ( g = −0.28; 95% CI, −0.62, 0.06), with studies generally showing reductions in negative affect in both settings. Further research with additional populations, settings, antecedent conditions, and durations would provide a more robust understanding of differences in effects between these two ways to enhance mood by viewing nature. (shrink)

Next SectionIn an online study conducted separately in the UK and the US, participants rated the acceptability and fairness of four interventions: two types of financial incentives and two types of medical interventions. These were stated to be equally effective in improving outcomes in five contexts: weight loss and smoking cessation programmes, and adherence in treatment programmes for drug addiction, serious mental illness and physiotherapy after surgery. Financial incentives were judged less acceptable and to be less fair than medical interventions (...) across all five contexts. Context moderated the relative preference between rewards and penalties: participants from both countries favoured rewards over penalties in weight loss and treatment for serious mental illness. Only among US participants was this relative preference moderated by perceived responsibility of the target group. Overall, participants supported funding more strongly for interventions when they judged members of the target group to be less responsible for their condition, and vice versa. These results reveal a striking similarity in negative attitudes towards the use of financial incentives, rewards as well as penalties, in improving outcomes across a range of contexts, in the UK and the USA. The basis for such negative attitudes awaits further study. (shrink)

This chapter describes the potential far‐reaching consequences of contemplative higher education for the fields of science and medicine.

We report the identification of a recurrent, 520-kb 16p12.1 microdeletion associated with childhood developmental delay. The microdeletion was detected in 20 of 11,873 cases compared with 2 of 8,540 controls and replicated in a second series of 22 of 9,254 cases compared with 6 of 6,299 controls. Most deletions were inherited, with carrier parents likely to manifest neuropsychiatric phenotypes compared to non-carrier parents. Probands were more likely to carry an additional large copy-number variant when compared to matched controls. The clinical (...) features of individuals with two mutations were distinct from and/or more severe than those of individuals carrying only the co-occurring mutation. Our data support a two-hit model in which the 16p12.1 microdeletion both predisposes to neuropsychiatric phenotypes as a single event and exacerbates neurodevelopmental phenotypes in association with other large deletions or duplications. Analysis of other microdeletions with variable expressivity indicates that this two-hit model might be more generally applicable to neuropsychiatric disease. © 2010 Nature America, Inc. All rights reserved. (shrink)

Just Ecological Integrity presents a collection of revised and expanded essays originating from the international conference "Connecting Environmental Ethics, Ecological Integrity, and Health in the New Millennium" held in San Jose, Costa Rica in June 2000. It is a cooperative venture of the Global Ecological Integrity Project and the Earth Charter Initiative.

In lieu of an abstract, here is a brief excerpt of the content:242 HISTORY OF PHILOSOPHY his political and religious predispositions prodded him to demonstrate that the roots of modern science were in the Christian Middle Ages. Sarton's particular foibles are best understood by referring them to his pacifist commitments and the moralistic assumption that the values of science are transferable to other human endeavors. Categories such as inductivism, conventionalism and Popperianism are of little help in gaining historical understanding. For (...) this, they are in fact Platonic ideals which have little heuristic value. I would venture that a truly historical historiography of science would aid us in spotting errors in the past and help us in the future. My guess is that a good analysis would reveal a major source of trouble to have stemmed from preconceived notions which the history of science was meant to illustrate. Surely some of them have been philosophical in character, and even Baconian or conventionalist. But until recent times, most of these preconceptions have stemmed from religious, nationalistic, or personal motivations, or from scientists who wanted support for a particular concept. I agree with Agassi only in the suggestion that a parti pris was at the root of our troubles. Why, then, substitute a Popperian preconception for a conventionalist one? Why not, on the contrary, combat their distorting influence and reduce their impact? This is in fact what has happened in recent times. As the history of science has fallen into the hands of a gradually organized profession, the blatant motivations --of any type--which colored past historical writings have slowly receded. By a constant and critical confrontation of opposing views among specialists, the purpose for examining the history of science has slowly been transformed. The older external motivations have given way to an interest in the subject for its own sake and a gradual transformation has been in the making for the last few decades. As happens in other human endeavors, professionalization has already raised the standards in the discipline and there is every reason to think it will continue to do so in the future. We need not really be as pessimistic as Agassi, nor embrace his particular salvation. ROGEa HAm~ University o] Cali]ornia, Berkeley A MEDIEVAL ANALYSIS OF INFINITY IN THE COURSEof arguing that time must have had a beginning, St. Bonaventure (1221-74) put forward a demonstration which in some ways seems to anticipate Cantor's definition of infinity.1 Bonaventure pointed out that, if the world were infinitely old, then there would have been an infinite number of annual revolutions of the sun around the ecliptic. But during each such period there occur (roughly) twelve revolutions of the moon, i.e. lunar months or lunations. Thus there would be one infinity which was twelve times another--which, says Bonaventure, is impossible. This attempted proof might be formulated as the following For other adumbrationsof this definition,see I. Thomas,"A TwelfthCentury Paradoxof the Infinite,"Journal o] Symbolic Logic, XXIII (1958), 133-134, and W. & M. Kneale, The Development of Logic (Oxford,1962),p. 440. NOTES AND DISCUSSIONS 243 reductio ad absurdum, in which a revolution of the sun is specified as the period between successive vernal equinoxes. If there could be an infinite set of past lunations, then clearly it could be put in a one-to-one correspondence with a proper sub-set of itself--viz., with the set of past lunar months during which vernal equinoxes occurred. But this consequence is preposterous; no set could be so correlated with its own sub-set. Therefore the set of past lunar months cannot be infinite, and the world must have had a beginning. The passage, which is found in Bonaventure's commentary on the Sentences of Peter Lombard, reads as follows :2 Si mundus est aeternus, revolutiones solis in orbe suo sunt infmitae ; rursus, pro una revolutions solis necesse est fuisse duodecim ipsius lunae: ergo plus revoluta est luna quam sol; et sol infinities: ergo infinitorum ex ea parle, qua infinita sunt, est reperire excessum. Hoe autem est impossibile : ergo etc. PA~-r~asoN BROWN Harpur College, State University o] New York Sententiarum L/b. H, Dist. I, P.I, Art. I, Quaest. II, as found in S. Bonaventurme, Opera Omnla... (shrink)

The modal interpretation of quantum mechanics allows one to keep the standard classical definition of realism intact. That is, variables have a definite status for all time and a measurement only tells us which value it had. However, at present modal dynamics are only applicable to situations that are described in the orthodox theory by projective measures. In this paper we extend modal dynamics to include positive operator measures. That is, for example, rather than using a complete set of orthogonal (...) projectors, we can use an overcomplete set of nonorthogonal projectors. We derive the conditions under which Bell's stochastic modal dynamics for projective measures reduce to deterministic dynamics, showing that Brown and Hiley's generalization of Bohmian mechanics [quant-ph/0005026, ] cannot be thus derived. We then show how deterministic dynamics for positive operators can also be derived. As a simple case, we consider a Harmonic oscillator, and the overcomplete set of coherent state projectors. We show that the modal dynamics for this POM in the classical limit correspond to the classical dynamics, even for the nonclassical number state |n>. This is in contrast to the Bohmian dynamics, which for energy eigenstates, the dynamics are always non-classical. (shrink)